Honeycomb panels have heretofore been provided consisting of an array of hexagonal cells made of strips of flat material glued or otherwise bonded together and nested so that each wall of one cell is shared with walls of adjacent cells to provide a structure which, depending on the type of materials used, can vary from being quite rigid to being flexible. Whereas structures of the former type are suitable for making lightweight panels for use in walls, aircraft structures, boat hull structures and other configurations where rigidity, strength and light weight are important considerations, when crushed, these structures exhibit little if any recovery and are thus permanently degraded. In structures of the latter type wherein the honeycomb material is flexible, a cushioning structure can be provided which is resilient and energy absorbing. However, prior flexible honeycombs have been deficient in one or more of the properties of resiliency, squeezability, shape recovery, softness, breathability, water absorbency, conformability, and the like.
Resilient honeycombs are often made from thermoplastic elastomeric strips that are intermittently bonded together at staggered intervals along the length of the strip. Facings are generally applied across the wall edges of the cells to enclose them and maintain the shape of the honeycomb. The thermoplastic elastomeric materials used provide resiliency so that the honeycomb returns to its original shape following deformation. Resilient honeycombs are used for shock absorption and vibration dampening as well as lightweight insulation.
Examples of resilient honeycombs, methods of making and uses therefor include Landi, et al., U.S. Pat. No. 5,039,567, Landi, et al., U.S. Pat. No. 5,180,619, Landi U.S. Pat. No. 5,110,653, Landi U.S. Pat. No. 5,203,607, Landi 5,122,405 and Landi, et al., U.S. Pat. No. 5,403,642. These prior art honeycombs are made from thermoplastic elastomeric materials, such as polyurethane, which are not porous, using a compression bonding method followed by expansion of the bonded stack. At least one facing sheet is required to maintain the honeycomb structure in the expanded state and to encapsulate air within the cells. In the absence of a desire for air encapsulation, a facing sheet or some other means, such as heat flanging, is required to maintain the expanded structure of the honeycomb. These prior art honeycombs rely substantially on the elastomeric nature of the material and encapsulated air within the cells to provide shock absorbency, vibration dampening and shape recovery and, as a result, are denser and stiffer than otherwise desirable, often requiring that they be cushioned with another material, such as a foam layer. They also tend to have a relatively high compressive strength value which makes them harder to conform to a desired shape. When air flow from cell to cell is desired, it is necessary to perforate the elastomeric materials of these patents, as in U.S. Pat. No. 5,180,619 and 5,203,607.